Recently, the request for implementing high capacity and high speed in wireless communication has been rapidly increased, and thus researches for methods of improving the use efficiency of limited frequency resources have been actively performed. As one of the methods, a method of using a spatial region has attracted attention.
One of the technologies using the spatial region is an adaptive array antenna (adaptive antenna). By using this technology, a desired wave signal is received with a high intensity while suppressing an interference wave signal by adjusting the amplitudes and phases of wave signals using weighting coefficients (hereinafter, referred to as weights) which are multipliers for received signals, whereby the co-channel interference is reduced, and accordingly, the system capacity can be improved.
In addition, a different technology using the spatial region is a spatial multiplexing technology which uses physical channels having the same frequency and the same sign at the same time by using spatial orthogonality in a propagation channel for transmitting different data series to different terminal equipments.
The spatial multiplexing technology is disclosed in Non-Patent Document 1, etc. In a spatial multiplexing wireless base station and a terminal equipment which use this technology, a spatial multiplexing transmission can be performed in a case where a spatial correlation coefficient between terminal equipments is less than a predetermined value, whereby the throughput and the number of simultaneous users of the wireless communication system can be improved.    Non-Patent Document 1: T. Ohgane et al, “A study on a channel allocation sc heme with an adaptive array in SDMA,” IEEE 47th VTC, Page. 725-729, vol. 2(1997)